Prof.T.Shivaji Rao,
Director, Center for Environmental studies,
GITAM University, Visakhapatnam
http://www.dianuke.org/wp-content/uploads/2012/08/Chap_7-CAG-ON-AERB.pdf
http://www.dianuke.org/wp-content/uploads/2012/08/Chap_7-CAG-ON-AERB.pdf
http://www.dianuke.org/lessons-of-chernobyl-and-fukushima-nuclear-safety-is-an-oxymoron/
http://home.ccr.cancer.gov/inthejournals/bonner.asp
[DNA Repair fails in old and sick people]]
http://www.pibchennai.gov.in/karuvoolam/Releases%202012/January%202012/KKNPP31.01.2012.pdf [Govt.of India Expert Group Report on kudankulam safety]
http://home.ccr.cancer.gov/inthejournals/bonner.asp
[DNA Repair fails in old and sick people]]
http://www.pibchennai.gov.in/karuvoolam/Releases%202012/January%202012/KKNPP31.01.2012.pdf [Govt.of India Expert Group Report on kudankulam safety]
In the light
of major nuclear reactor explosions at Three Mile Island (TMI) in USA
(1979), Chernobyl in Russia (1986) and
Fukushima in Japan (2011) intelligent people question why we had ever started
nuclear power plants in the first instance? Why did people fail to realize how
dangerous the nuclear power was? Why we
failed to think about health risks to people living in the neighbourhood of
nuclear plants? Why people failed to estimate the most damaging consequences of
generating so much nuclear waste? Even
today most people refuse to think on these life and death issues due to perhaps
ignorance, apathy and lack of social responsibility.
INTRODUCTION:
But during
second world war the defeat of the enemy countries like the Nazi Germany and
aggressive Japan was a major issue for the Western countries like USA which
dropped killer Atom bombs over Hiroshima and Nagasaki to make Japan surrender. Subsequently a cold war developed between
Russia and America and the US wanted to produce nuclear weapons to show its
superior military strength to the world and for this purpose nuclear plants for
civil purposes like electricity production began to be built with the ulterior
motive of producing enriched Uranium and plutonium as byproducts to be used for
making nuclear weapons. People were not
informed about the health risks due to living around a nuclear plant. Risk was treated as a technical issue and was
left in the hands of the engineering experts.
Under the Atomic Energy Act, the Atomic Energy Commission in USA was
directed to promote nuclear power and in the process safety of nuclear power
had to be ensured on public demand. If more money were to be spent for nuclear
plant development the experts had to cut the costs and compromise with nuclear,
vice versa if safety has to be promoted it will slow down nuclear plant development
activities. Thus a contradiction developed between nuclear development and
nuclear safety and the later was given a very low priority.
NUCLEAR SAFETY BY RULE OF THUMB:
In the beginning,
the safety of nuclear plants was ensured by the simple law of locating the
reactors far away from human habitations.
In 1950 a thumb rule was used to link the power of the reactor with an
exclusion zone where people could not live and in case of a reactor explosion
people in the off-site area were not expected to be exposed to a fatal dose of
radioactivity. For small research
reactors the exclusion zone was one or 2
miles in radius and for larger plants
that supply electricity to the cities the exclusion zone would be 10 times
higher. But the cost of land acquisition
proved to be very high. In order to
overcome this problem the designers came up with the idea of putting the
reactor inside a large steel shell, a containment building that would keep the
radioactive pollutants from escaping to outside environment in case of an
accident.
NUCLEAR ACCIDENTS:
As nuclear
reactors began to increase in 1960’s questions were raised on the safety of the
reactors if the pressure vessel were to burst.
The designers who knew the capabilities of normal steel became
uncomfortable that the neutron bombardment of the pressure vessel can make the
conventional steel brittle and liable to break, although under conditions it
would normally be quite strong. Atomic
Energy Commission assumed that during a
loss of coolant accident even if the coolant stopped and the reactor core
melted, yet the containment building would stop the radioactive gases from
escaping into the atmosphere. But in
1966 it was realized that in a 1000MW reactor, the fuel gets so hot after a
loss of coolant accident that it might bum (pass) through the concrete and flow
into the earth in a China syndrome. Such
an accident would breach the containment and release poisonous radioactivity
into environment by somehow generating enough gas pressure to blow a hole in
the containment. Consequently to ensure
that the core would not melt the
engineers designed more and more sophisticated systems and added new backup
systems to the existing back up systems without knowing whether they work in
the real field as planned in their imaginary world.
NUCLEAR SAFETY BY PROBABILISTIC ASSESSMENT:
The forces
generated in a reactor by a loss of coolant accident and sudden heating and
then a flood of cold water from the emergency core cooling system would be
violent and unpredictable. Nobody knows
as to what happens to the fuel rods when they were heated and cooled so
brutally and a great deal of testing and research studies must be made to find
out the real facts. One of the nuclear
experts argued that nobody can ensure absolute safety in case of a nuclear
accident and nobody can say that no radiation would escape into the environment
to threaten the public health. During an
emergency if a core cooling system fails there is a chance that the containment
could be breached and radioactive materials get into the atmosphere. The experts began to admit that a severe
accident was possible but its probability will be so small that reactors will
be regarded as safe are to put it other
words the reactor safety became “probabilistic” and not “deterministic”.
Subsequently
the probabilistic risk assessment came into being. It evaluated risk by taking into account both
the probability of a certain accident occurring and the consequences of that
accident. If an accident occurs once in
a million years of reactor operation and kills a thousand people, it is
equivalent to an accident that occurs once in a 1000 years with only one death
expected and this was accepted by the engineers who would establish a numerical
target for reactor safety and by expecting one death by radiation accident for
every 1000 years of reactor operation.
The engineers set out to reach that goal. Moreover to pronounce a reactor as a safe one
engineers need not guarantee that certain accidents could never happen but only
to ensure that they were unlikely. This
approach admits that major accidents were indeed possible and such an accident
might be occur one in a million shot and an attempt was made to calculate the
likelihood of a major nuclear accident by Prof.Rasmussen in 1974 (a nuclear
engineering professor at MIT). By
visualizing various ways in which an accident can occur he considered loss of
coolant accident. His report showed a
core melt down once in every million years of reactor operation and major
accident once in a billion years of reactor operation. It means that a person is likely to die from
a nuclear accident as from being hit a meteor.
THREE MILE ISLAND NUCLEAR ACCIDENT DUE TO HUMAN
FAILURES:
But TMI
accident occurred in a reactor melt down in 1979. Such accident was expected to
occur once in every 17000 reactor years and not once in every million reactor
years as propagated by the US Atomic energy Commission. But the occurrence of TMI accident shocked
the nuclear experts. Before TMI accident in 1979 most of the safety
efforts made by nuclear authorities aimed at improving the equipment. By making sure that everything is designed,
built and maintained properly and automatically it was thought that safety is
bound to follow. But a piece of
malfunctioning equipment played a key role in the TMI reactor accident in 1979
and the Kemeny enquiry report on this accident concluded that the problems with
additions to equipment were only a small part of it. More worrisome was the performance of the
operators who were running the reactors.
They had been poorly trained and poorly prepared for an emergency of the
type that caused the TMI accident. Not
only did they not take the corrective steps to solve the problem but their
actions made it worse.
Kemeny
commission felt that the errors committed by the nuclear operators are only a
part of a more general feeling of the nuclear plant and its management due to
several reasons and emphasized that a reactor operation demands different kinds
of management and organization capacities than those needed for operating an
electricity producing coal based thermal plant.
Such plants run at full power until some component breaks and then after
re-fixing the broken part the plant is started again and there is no serious
concern about nuclear safety, preventive maintenance and preventive actions for
safety. Such plants are simple and do
not endanger life systems even when they breakdown. Many industries develop these attitudes to
run nuclear plants and hence such attitudes did not work. The operation of a nuclear plant requires an entirely different
institutional culture than that adopted for a thermal plant. On examining the TMI nuclear accident experts
realized that major accidents like nuclear explosions can be caused by little
things. But the thinking on nuclear
safety was focused to respond to major failures such as a large pipe
breakage. By interlinking the chain of
events that caused TMI accident one can prove that many minor mistakes during
operation can cause a major disaster.
Animation model of Nuclear plant for better understanding of its working.see website
http://www.whatisnuclear.com/articles/nucreactor.html
http://www.whatisnuclear.com/articles/nucreactor.html
For more reliability either 2 or 4 steam generators and the
required main coolant pumps are used.
Hot water at 2200 psia or 150 bars is pumped into the pressure vessel
containing the reactor core for cooling the very hot fuel elements in the core
water is distributed by a nozzle system to the core. Reactor coolant pumps transport the hot
coolant to steam generators where steam is produced and fed to the turbine. The coolant from turbine is fed to a
condenser and then it is fed by feed water pumps again to steam generators and
the condenser waste water is return to the coolant pond, river or ocean or to
the cooling towers which work as heat sinks.
The
beginning of the TMI accident started at 4AM when the pumps that transport water
to the steam generators failed due to human errors and equipment malfunctions
as seen from the pictures of a pressurized water reactors. There are two water supply loops, one
carrying hot water to the reactor and then to the steam generator and then returned
to the reactor. The second loop sends
water into steam generator where it is converted into steam and it drives
through turbine and in the process the steam gets converted into water which is
pumped back to the steam generator after heating and this secondary loop that
stopped functioning due to pumps shutdown.
As the secondary loop has failed the primary reactor cooling system also
failed to transport the heat to the steam generator and the primary loop began
to get over heated and expanded and thereby pressure increased in the reactor
and immediately the control rods dropped into the reactor core to absorb
neutrons and it killed the chain reaction simultaneously the automatic valve
opened and relieved the pressure in the reactor vessel as anticipated. But unfortunately after releasing enough
pressure the relief valve should have closed again but it did not and this
malfunction was reflected by an indicator in control room and a signal was sent
to close the valve. Unfortunately for
unknown reasons the valve did not close and the control room operators could
not know that crucial fact.
After 2
hours firstly the steam and subsequently a mixture of water and steam escaped
through the open valve and this caused the pressure to drop in the primary cooling
system after a few minutes of pressure drop it triggered the startup of high
pressure injunction pumps that sprayed water into the system. Since the operators misunderstood the
happenings of the reactor they closed one pump and cut back on the other to the
point where it could not make up for the water that was getting lost as steam
through the open relief valve. The
operators thought that they were doing what they have been trained to do and
they never could understand that they were making matters much worse by
creating opportunity for promoting the disaster. Consequently the coolant in the primary
reactor system boomed into a very turbulent mixture of water and steam.
After one and half hours the operators decided
to close the pumps that circulated coolant through the reactor to the steam
generators and back. Once again the
operators failed for a second time to understand the happenings inside the
reactors and they believed that they merely implemented the standard
procedures, and they never understood that the cutting of the reactor pumps has
only added fuel to the fire because the removal of this last bit of cooling
action in the core became the cause of the disaster. Soon after 50% of the core
was uncovered and consequently the core temperature shot up, melting some of
the fuel and thereby releasing highly radioactive poisonous pollutants and
radioactive gases escaped from the containment building into the atmosphere but
fortunately it did not cause much damage.
After two-and-half hours of the accident the operators found that the
pressure relief valve had never shut down and they closed it off. After another 12 hours the operators
succeeded in re-establishing cooling to the reactor core and started to bring
the reactor system back to normal temperatures.
Inspite of the restoration of the reactor still the accident resulted in
the evacuation of more than 2 lakh people within a radius of 32km from the
reactor and it caused huge financial losses to the government and the people
suffered heavily.
The TMI
accident shows that the chain of events that occurred during the accident were
such that no expert performing a probabilistic risk assessment could have imagined
much ahead of the time of the accident. The chain of events makes it easy for anybody
to try to blame the reactor operators.
Unfortunately they certainly overlooked the open pressure relief valve,
and they closed down the water cooling injection pumps and so plenty of blame
can be attributed to the operators. But
the designers also failed to incorporate any warning system in the control room
to show whether pressure relief valve had closed. It is known only that an indicator helped to
send a signal to close down pressure
relief valve. Surprisingly the American
Nuclear Regulatory Commission already knew that in a similar accident earlier
at another reactor a relief valve had got stuck open and created a problem. But this information was not sent to other
nuclear plants to warn them that the valve might create a similar problem
sometime or the other. The management
operated the nuclear reactors without correcting such little problems and hence
such work culture created a sloppiness that contribute to this accident. Even earlier there was a steady leak of reactor coolant
from a faulty valve and during the accident the operators who noted abnormal readings
that indicated the non-closure of the pressure valve was considered by them to
have been caused by the leak instead of
a faulty open pressure valve. Such small
faults often lead to a big disaster in a nuclear reactor.
COMPLEXITY OF REACTOR SYSTEM AS A MAJOR
CULPRIT FOR REACTOR EXPLOSIONS: But more than these innumerable small
faults in a reactor operation the major
accident occurred due to the abnormal culprit which is the complexity of the
system. The complexity of the system
provides an opportunity where innumerable minor faults could interact to
produce a major nuclear disaster and it makes it next to impossibility for the
operators to comprehend what is really going on in a reactor until it is too
late. According to political scientist
Aaron Wildavsky that because of complexity and the interactions in a nuclear
plant the mere addition of engineered safety devices like defence in depth and
other procedures will at some point of time actually decrease the safety in a
nuclear power plant. The TMI accident is
an example of how this phenomena works.
For instance the control room of TMI plant had 600 alarm lights, each
one considered by itself is promoting safety as it indicated when something is
going wrong. But the total effect in a
serious accident resulted in total confusion as many alarm’s went off and the mind could not easily grasp
what was happening.
Charles
Perrow another expert argues that such complex and tightly interconnected
technologies involved in nuclear reactors are by their very nature highly
unsafe. Since so many components will be
interacting with each other, there are many different ways through which an
accident can happen and that accidents are an inevitable characteristic of the
technology and such accidents are called “normal reactor accidents”. Moreover such complex technologies cannot be
made safe by constantly adding extra safety systems because that would increase
only complexity and creates more ways by which something could go wrong. The requirements for successful control of
some complex technologies are accompanied by inherent contradictions. What happens in one section of a nuclear
plant can drastically influence the events in other sections and some sort of
central control is necessary to ensure that actions in one section do not cause
unanticipated and hazardous consequences in another section. Such control can be implemented by central
management that approves all actions.
Otherwise such control can be exercised in the form of a rigid set of
rules and regulations governing all actions throughout the plant. But since the technology is so complex and
unpredictable, the operators of the reactor need the necessary freedom to
respond quickly and imaginatively to special circumstances as and when they arise. Hence both rigid central authority and local
discretion are highly desirable and unfortunately it is impossible to have
both. Hence a nuclear reactor is always
vulnerable to one type of accident or another, either one caused by failure to
adopt quickly to an unanticipated problem or else one that is created by not
coordinating all the relevant actions throughout the plant.
Perrow
argues that many technologies including nuclear power experience the same
inherently contradictory demands like chemical plants, genetic engineering,
aircraft and nuclear weapons. For such
complex technologies the accidents should be considered not as anomalies but as
a normal part of the process. However
the frequency of accidents can be reduced by improved design, better training
of personnel and efficient maintenance but they will be always with us. Society must weigh the cost of these normal
accidents against the benefits of the technology. For chemical plants like the sugar mills the
cost of accidents are small and are borne by the companies while the cost of
shutting down would be high as there is nothing to replace them. But in the case of nuclear accidents the
costs of damage would be bearable and also there are several other ways of
generating electricity not only by nuclear plants but also by alternate plants based on fossil fuels and renewable
energy sources like solar, wind and bio-energy and geo-thermal plants.
In modern times
nobody believes any longer that it is possible to engineer for complete safety
of a nuclear reactor, to determine the maximum credible accident and then assure
that nuclear reactor does not threaten anyone.
The best that can be done in the nuclear field is to attempt to make the
disastrous accidents very unlikely. Moreover the complexity of nuclear
technology can amplify the risk to the
people and the environment. Further the
more complex technology the more ways something can go wrong. In a tightly coupled system of the nuclear
reactor the number of ways that something can go wrong increases exponentially
with the number of components in the system.
Such complexity also makes nuclear reactor system more vulnerable to
errors both man-made and natural. Even a small mistake may trigger the system behave
in many unpredictable ways making it difficult for the reactor operators to
understand what is happening and to restore the system to normalcy and it is
likely that the operators will make further mistakes that may result in a
disaster.
According to some experts the fuel gets yellow-hot at its
core, attaining a temperature of 4100oF (2250oC) while
the metal casing around the fuel is kept at 650oF (350oC)
by the cooling water. If due to an
accident the coolant water gets interrupted for just a few seconds the fuel
temperature rises rapidly and the zirconium casing begins to break at 1800oF
(1000oC) and melts at 3350oF (1850oC) The
actual danger comes when the hot fuel begins to lump together in a molten mass
that can explode the containment or seep into the ground, a process known as
“Chinese-Syndrome”, and release massive quantities of radioactivity into the
air, water and soil environment.
If the main pipe in the primary cooling breaks, immediately
the control rods eliminate the nuclear fission process, halting the
activity. But the radioactivity in the already disintegrating
fission products cannot be arrested. In a 650MW plant, the heat formation
by the radioactive disintegration process amounts to roughly 200MW three
seconds after the reactor is switched off, 100 MW after one minute, 30MW after
one hour and 12MW after 24 hours.
IT MEANS EVEN A DELAY FOR ONE MINUTE IN COOLING WATER SUPPLY FOR THE REACTOR
MAY CAUSE A CORE MELT DOWN AND A REACTOR EXPLOSION AS IN FUKUSHIMA,JAPAN
LOSS OF COOLANT LEADING TO REACTOR EXPLOSION
(Diminishing heat and
sequence of failures due to loss of coolant after the reactor is
stopped.)
Time
|
Heat formation
|
Remarks
|
0
|
650
MW
|
Reactor stopped by control rods
|
3
Seconds
|
200
MW
|
Heat formation
|
15
Seconds
|
--
|
Fuel casing begans to fail
|
30
Seconds
|
--
|
Boiling layer of emergency coolant
|
45
Seconds
|
--
|
Reactor core melts
|
60
Seconds
|
--
|
Reactor core collapses
|
1
hour
|
30
MW
|
--
|
24
hours
|
12
MW
|
--
|
Months
|
Diminishing
heat
|
--
|
The above table shows that if the operators cannot stop
reactor core melt conditions within 45
seconds. A nuclear explosion is bound to occur. Can we find such strict work
culture among Indian Nuclear plant operators?
Hence nuclear safety is purely a myth because accidents are bound occur
and ruin public health.
WHY NUCLEAR SAFETY IS IMPOSSIBLE AT KUDANKULAM REACTORS ?
http://www.rerf.jp/radefx/basickno_e/radcell.htm
DAMAGE TO LIFE FORMS IS OFTEN IRREVERSIBLE AND INEVITABLE MAKING NUCLEAR SAFETY A PIE IN THE SKY AND HENCE PEOPLE MUST OPPOSE THEM:
DAMAGE TO LIFE FORMS IS OFTEN IRREVERSIBLE AND INEVITABLE MAKING NUCLEAR SAFETY A PIE IN THE SKY AND HENCE PEOPLE MUST OPPOSE THEM:
When
an electron passes through a biological cell the electron releases its
energy along its path (called a track) by interacting with the electrons
of nearby molecules. The energy thus released is absorbed by atoms
near the track causing excitation ( a push in the orbit of an electron
to a higher energy level) or ionization (release of an electron from the
atom) and the residue unstable atoms are known as radicals
and are chemically highly active. X-ray and gamma rays unlike Beta
particles release high speed electrons from atoms first. Positively
charged particles transfer energy to molecules in the cells electrically
uncharged neutrons impact of the nuclei of hydrogen atoms namely
protons. Since the masses of the proton and neutron are similar the
impact results in an elastic scattering process as occurs in Billiards
game. The ejected protons work like charged protons. Ionizations due
to radiation act directly on cell molecules or indirectly on water
molecules causing water derived radicals which react with nearby
molecules causing breakage of chemical bonds or addition of oxygen atoms
by oxidation of the affected molecules. The major effect in biological
cells is at DNA breaks either in single strand or double strands and
the later is important biologically. Single strand breaks can be
repaired normally because of the double stranded nature of the DNA(the
two strands complement each other so that an intact strand serves as a
template for repair of its damaged opposite strand) In case of double
strand breaks the repair is more difficult and the erroneous rejoining
of broken ends may occur and such misrepairs cause mutations,
chromosome abrasions or cell death.
Radiations
differ not only by their components like electrons, protons and
neutrons but also by their energy. Radiations by neutrons and alpha
particles cause dense ionization along their track and are called High
Linear Energy Transfer ,High LET radiation that is energy released per
unit length of the track. Low LET radiations by X-Rays and Gamma rays
produce ionizations sparsely along their track and homogeneously within
the cell. High LET radiations release energy in a small region of the
cell and the localized DNA damage caused by High LET radiations is more
difficult to repair than the diffuse DNA damage caused by the sparse
ionizations from Low LET radiations. The same radiation dosage produce
the same total number of ionizations with the difference that Low LET
radiation causes sparse ionizations whose damaging effects can be
normally repaired while the High LET radiation causes dense ionization
along their track causing double strand breaks which are more difficult
for repair and hence are bound to cause cell deaths or mutations
resulting in cancer and other forms of illness.
http://en.wikipedia.org/wiki/Relative_biological_effectiveness
TYPES OF IONIZING RADIATIONS
Weighting factors WR (formerly termed Q factor)
used to calculate equivalent dose |
||
Radiation
|
Energy
|
wR
(also Q)
|
1
|
||
< 10 keV
|
5
|
|
10 keV - 100 keV
|
10
|
|
100 keV - 2 MeV
|
20
|
|
2 MeV - 20 MeV
|
10
|
|
> 20 MeV
|
5
|
|
> 2 MeV
|
2
|
|
20
|
||
TYPES OF IONIZING RADIATIONS
General Characteristics
http://www.rerf.jp/radefx/basickno_e/radcell.htm
HOW LOW DOSE RADIATION DAMAGES HUMAN CELLS
Cells will be damaged by ionizing radiation directly or indirectly depending on the types of atoms affected in the cells. A direct effect of ionization breaks the atoms of DNA molecules or critical components of cells that regulate cell function. The cells either die or mutate because of direct damage to the DNA or other critical components. An indirect effect of ionization damages cells by causing structural changes within the cells.
http://www.marts100.com/Effects.htm [Damaging impacts of ionisation, see links also]
Water molecules in cells get decomposed into hydrogen (H) and (OH) ions due to ionization. These fragments or "free radicals" generally recombine as water or theyform compounds such as hydrogen peroxide (H2O2). Water does not harm a cell; however hydrogen peroxide is toxic and could lead to the destruction of a cell. The indirect effect predominates over the direct effect because a DNA molecule is a very small part of human cells whereas water constitutes 65-90% of human cells.
Our bodies have organs, and the organs are made of tissues and the tissues are made of cells and the cells are made of molecules, and finally molecules are composed of atoms. All biological damage from radiation commences at the lowest level with damage to atoms which are in the cells and progresses to the highest level with damage to the whole body.
Particulate vs. Electromagnetic Radiations: Particulate Radiations are sub-atomic particles with mass (e.g., alpha and Beta particles, electrons, neutrons). EM Radiations (X-rays and gamma rays) have no mass and no charge.
High vs. Low Energy Radiation: Absorption of radiation is the process of transferring the energy of the radiation to the atoms of the media through which it is passing. Higher energy radiation of the same type will penetrate further. Usually expressed in KeV or MeV (103 or 106 electron Volts). 1 eV = 1.6 x 10-19 Joules = 1.6 x 10-12 ergs
High vs. Low Linear Energy Transfer (LET) to absorbing material: LET is measured by the ionization density (e.g., ion pairs/cm of tissue) along the path of the radiation. Higher LET causes greater biological impact and is assigned a higher Quality Factor(QF). Example QF values: X, gamma, and beta have QF = 1; alpha QF=20; thermal neutrons QF=3; "fast" neutrons (>10 KeV) QF = 10; fission fragments QF>20.
- Characteristics of Common Radiations
Alpha Particles (or Alpha Radiation): Helium nucleus (2 neutrons and 2 protons); +2 charge; heavy (4 AMU). Typical Energy = 4-8 MeV; Limited range (<10cm in air; 60µm in tissue); High LET (QF=20) causing heavy damage (4K-9K ion pairs/µm in tissue). Easily shielded (e.g., paper, skin) so an internal radiation hazard. Eventually lose too much energy to ionize; become He.
Beta Particles:High speed electron ejected from nucleus; -1 charge, light 0.00055 AMU; Typical Energy = several KeV to 5 MeV; Range approx. 12'/MeV in air, a few mm in tissue; Low LET (QF=1) causing light damage (6-8 ion pairs/µm in tissue). Primarily an internal hazard, but high beta can be an external hazard to skin. In addition, the high speed electrons may lose energy in the form of X-rays when they quickly decelerate upon striking a heavy material. This is called Bremsstralung (or Breaking) Radiation. Aluminum and other light (<14) materials and organo-plastics are used for shielding.
Note: Beta particles with an opposite (+) charge are called positrons. These quickly are annihilated by combination with an electron, resulting in gamma radiation (see Pair Production below).
Neutrons: Neutron ejected from a nucleus; 1 AMU; 0 Charge; Free neutrons are unstable and decay by Beta emission (electron and proton separate) with T½ of approx. 13 min. Range and LET are dependant on "speed": Slow (<10 KeV), "Thermal" neutrons, QF=3, and Fast (>10 KeV), QF=10. http://www.osha.gov/SLTC/radiationionizing/introtoionizing/ionizinghandout.html
HOW LOW DOSE RADIATION DAMAGES HUMAN CELLS
Cells will be damaged by ionizing radiation directly or indirectly depending on the types of atoms affected in the cells. A direct effect of ionization breaks the atoms of DNA molecules or critical components of cells that regulate cell function. The cells either die or mutate because of direct damage to the DNA or other critical components. An indirect effect of ionization damages cells by causing structural changes within the cells.
http://www.marts100.com/Effects.htm [Damaging impacts of ionisation, see links also]
Water molecules in cells get decomposed into hydrogen (H) and (OH) ions due to ionization. These fragments or "free radicals" generally recombine as water or theyform compounds such as hydrogen peroxide (H2O2). Water does not harm a cell; however hydrogen peroxide is toxic and could lead to the destruction of a cell. The indirect effect predominates over the direct effect because a DNA molecule is a very small part of human cells whereas water constitutes 65-90% of human cells.
Our bodies have organs, and the organs are made of tissues and the tissues are made of cells and the cells are made of molecules, and finally molecules are composed of atoms. All biological damage from radiation commences at the lowest level with damage to atoms which are in the cells and progresses to the highest level with damage to the whole body.
PEOPLE MUST FIGHT TO SAVE THEIR RIGHT TO LIFE, RIGHT TO HEALTH AND RIGHT TO LIVELIHOOD AT ANY COST:
When
India became independent Mahatma Gandhi addressed a public meeting on
the occasion. He said “by making Pandit.Jawahar Lal Nehru as the Prime
Minister of India I call him an uncrowned King of India. Like anyone of
us he is a humanbeing and all of you know that to err is human. In
course of his work to uplift the nation he will plan and execute
several developmental projects during the course of administration he
may commit some errors who will correct such errors. His Minister or
his administrative officers will not dare to point out his mistakes and
rectify them and then who will take the responsibility to put the
nations destiny on the right track”. Since none of them people
presented the meeting opened their mouths he told them point blank “ it
is you, the people of this great social welfare state in the democracy
who have to correct even the mistakes of a Prime Minister. If you do
not come forward to rectify such defects you are unfit as responsible
citizen of the great social welfare state. Similarly Prime Minister
Mrs.Indira Gandhi also wanted all the responsible citizens to protect
public interest and for the purpose amended article 51A and introduced
sub clause “g” by which she proclaimed that it is the first duty o the
responsible citizen to protect the water, the air, the forests, the wild
life and to develop compassion for all living creatures. “That is why
it has been always said that eternal vigilance is a price that the
Indian people have to pay to sustain their democracy. Thus it is the
people of India who have to fight against the anti peoples actions
perpetrated by the Government at the state and Central levels to
safeguard the health and welfare of the present and future generations
of the people in India. Coming to the case of Kudankulam nuclear
reactors the people must play an active role to stop them as they are
just silent killers.
In
case of Kudankulam reactors it is better that the local people and
school children must collect funds by begging in Tamilnadu villages and
towns and present the money to the Chief Minister and Prime Minister for
abandoning the present reactors on the plea that in case these reactors
experience explosions on the pattern of Fukushima rectors, the people
have to pay a heavy penalty of Rs.4 lakh crores which will make the
state and the country fall into the trap of economic bankruptcy. Infact
in one of the villages of Cuddapah the school children who found that
their family members addicted to liquor are not only dying but also
ruining their families because the state Government has considered
liquor business as their main economic source of survival. The children
wanted to pay that amount realized through liquor sales to the state
Government to ban liquor sales so that the families will save their own
heads of families who are the bread winners. In Tamilnadu the
experiment can be copied and implemented to stop the reactors and
thereby stop the state Government do indirectly declare a nuclear war on
millions of people of South Tamilnadu.
Even
in history there are many instances when a Kingdom was invaded a
treacherous foreign ruler the local people used to fight against the
invasion or alternatively purchase peace by paying compensation money to
the invader. Veera Pandya Kattabhraman refused to yield to the
dictators of the treacherous British rulers so he was hanged in public.
Today the people of this historical Pandyan Empire have to save their
lives and of their progeny against the invasion by the people in the
North of Pandya Kingdom in Tamilnadu and those from the North India.
The Pandyans if they want the survival of their future generations they
must resort to this alternative course of action as followed by the
children of the Cuddapah village of Andhra Pradesh.
NOTE:The nuclear experts are feeding very false information on the damaging impacts of the routine radioactive pollutants released into the environment by stating that their concentrations in the environment will contribute only as a small fraction of the inevitable background level radiation experienced by the people. But they fail to tell the truth that the impact of the background level radiation causes lesser damage to public health and the environment while the manmade radioactive pollutants cause higher levels of damage because of the differences in their energy levels and the quality factors as discussed elsewhere in the article
RADIOACTIVE LIQUID EFFLUENTS(TRITIUM) RELEASED INTO NATURAL WATER (1973)
S.No.
|
Name
of Reactor
|
Liquid
waste
(Lakh
liters)
|
Activity
(Curies) |
%
contribution
|
|
Fission
Products
|
Tritium
|
||||
1.
|
San Onofre-1
|
90
|
4138
|
0.1
|
98.4
|
2.
|
Haddam Neck
|
270
|
3900
|
0.1
|
99.9
|
3.
|
Yankee (Rowe)
|
170
|
694
|
0.1
|
99.9
|
4.
|
Point Beach-1,2
|
58
|
577
|
0.1
|
99.8
|
5.
|
Surray-1,2
|
160
|
449
|
0.1
|
99.6
|
6.
|
Indian Point-1
|
88
|
139
|
0.9
|
99.0
|
2 comments:
Your content really informative as well as helpful for my
Nuclear Power Engineering Research and Development.
Your content really informative as well as helpful for my
Nuclear Power Engineering Research and Development.
Post a Comment